Revolver for a packaging machine

ABSTRACT

A revolver for use as part of a packaging machine for wrapping cigarettes in sheets of packaging material is disclosed. The revolver comprises article receiving means connected to a shaft to rotate therewith. The article receiving means is provided with a plurality of cells spaced at angular intervals around the axis of rotation, and each adapted to receive one block of cigarettes to be wrapped in a sheet of wrapping material, which is introduced into the cell prior to the cigarettes being introduced therein. Each cell is associated with a respective suction chamber defined between the outer wall of the cell and a perforate wall thereof. Each suction chamber, when connected to a source of vacuum pressure, serves to retain a sheet of wrapping material in contact with the perforate inner wall of the cell. Each cell is so dimensioned that the width of the cell - as measured by the distance separating two mutually parallel inner perforate wall portions thereof - is substantially less than the extent of these perforate wall portions - as measured in a direction extending generally radially of the axis of rotation. The shaft is provided with a plurality of longitudinally extending passages each in communication with a suction chamber of a respective one of the cells. The revolver is provided with valve means co-rotational with the shaft. Each of the longitudinal passages is selectively connected to the source of vacuum pressure via the valve means when and only when the respective cell is located in a predetermined range of angular positions relative to the axis of rotation.

United States Patent [191 Schmermund [451 Apr. 15, 1975 l l REVOLVER FOR A PACKAGING MACHINE {76] Inventor: Alfred Schmermund, Kornerstrasse 62, 5820 Gevelsberg, Germany [22] Filed: Nov. 8, 1973 [21] Appl. No.: 413,995

[30] Foreign Application Priority Data Nov. 30, 1972 United Kingdom 55334/72 [52] US. Cl 93/44.] R; 53/234; 93/12 C; 93/84 FF [51] Int. Cl ..B31b 1/12; B3lb 1/32 [58] Field of Search..... 53/234, 148; 93/12 C, 12 R, 93/44.l R, 84 FF, 8] R, 81 MT, 39.2, 39.3

[56] References Cited UNITED STATES PATENTS 2,608,039 8/1952 Abramowski 53/234 3,196,760 7/1965 Terry 93/44.] R 3,253,387 5/1966 Schmermund 53/234 3,331,293 7/l967 Mullaney 93/441 R [57] ABSTRACT A revolver for use as part of a packaging machine for wrapping cigarettes in sheets of packaging material is disclosed. The revolver comprises article receiving means connected to a shaft to rotate therewith. The article receiving means is provided with a plurality of cells spaced at angular intervals around the axis of ro tation, and each adapted to receive one block of cigarettes to be wrapped in a sheet of wrapping material, which is introduced into the cell prior to the cigarettes being introduced therein. Each cell is associated with a respective suction chamber defined between the outer wall of the cell and a perforate wall thereof. Each suction chamber, when connected to a source of vacuum pressure, serves to retain a sheet of wrapping material in contact with the perforate inner wall of the cell. Each cell is so dimensioned that the width of the cell as measured by the distance separating two mutually parallel inner perforate wall portions thereof is substantially less than the extent of these perforate wall portions as measured in a direction extending generally radially of the axis of rotation. The shaft is provided with a plurality of longitudinally extending passages each in communication with a suction chamber of a respective one of the cells. The revolver is provided with valve means co-rotational with the shaft. Each of the longitudinal passages is selectively connected to the source of vacuum pressure via the valve means when and only when the respective cell is located in a predetermined range of angular positions relative to the axis of rotation.

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mmk mm REVOLVER FOR A PACKAGING MACHINE BACKGROUND OF THE INVENTION The present invention relates to a revolver for use as part of a packaging machine for wrapping block-like articles in packaging material.

Co-pending United Kingdom Pat. application No. 48186/72 discloses a packaging machine for wrapping block-like articles such as cigarette blocks in packaging material. for example of paper or viscose or cellulose film. and the present invention concerns an improvement in, or modification of, the arrangement shown in that co-pending patent application.

SUMMARY OF THE INVENTION According to the present invention. there is provided a revolver for use as part of a packaging machine for wrapping block-shaped articles in packaging material, the revolver comprising a shaft mounted on a support to be rotatable about the longitudinal axis of the shaft. article receiving means connected to the shaft to rotate therewith. cavity defining means provided by wall members of the article receiving means to define a plurality of cavities spaced at angular intervals about the axis and extending in a generally radial direction relative to the axis. perforate members in each cavity in spaced relationship with the wall members of the respective cavity to define cells, each bounded by the perforate members and each adapted to receive one such article. and to define in each cavity a suction chamber between the perforate members and the wall members. the dimensions of each cell being greater in a direction radial of the axis than in a direction tangential at the cell to a circle passing through all of the cells. the circle having its centre on the axis and being disposed in a plane perpendicular to the axis.

Advantageously. the revolver further comprises a plurality of longitudinally extending passages defined in the shaft, each longtudinal passage communicating with a respective one of the chambers. and valve means co-rotational with the shaft. the valve means selectively connecting each longitudinal passage to a source of vacuum pressure on the respective one of said chambers being located within a predetermined range of angular positions relative to the axis.

It is advantageous to provide considerable space in the angular region between the individually adjacent cells of the revolver. such space facilitating the operation ofthe remaining parts ofa packaging machine with which the revolver is used. and such space also allowing. during traversing of the space by the individual revolvers, adequate time conveniently for the withdrawal of pushing members provided on packaging machine for transferring package from one revolver to another.

It may well be that the weight of a solid revolver would present difficulty in the operation of the packaging machine. in view of the quick acceleration and braking of the revolver which is required. For this reason. the entire revolver. and in particular the cells. are constructed of materials of low weight, for example light sheet metal. and the immediate mounting of the cells. which may take the form of holder members attached to a main body member in the form of a disc. are preferably also constructed with aperture provided for the purpose of reducing the total weight of the assembly required to rotate in operation of the packaging machine.

Preferably. a plurality of intermediate strip members are provided between the outer wall members and inner perforate members of each of the cells, to give support to the inner perforate members relative to the outer wall members.

Generally. four is the most convenient number of cells to provide on the revolver, but if desired eight cells, again equally angularly spaced from one another. may be provided. However. an eight-cell revolver may be expected to show fewer advantages than a four-cell revolver. for two reasons, Firstly, all the requisite operations can be carried out on each cigarette block in four cells, so that for efficient operation no more than four cells are absolutely necessary. Secondly. an eightcell revolver must. of necessity, be constructed with a larger size than a four-cell revolver. thereby giving a larger moment of inertial, with correspondingly increased power requirements for acceleraton and braking. In principle. any integral multiple of four cells may be provided on a revolver. but in practice a twelve'cell or sixteen-cell revolver. or an even larger one. is gener ally speaking too unwidely and cumbersome to operate efficiently.

BRIEF DESCRIPTION OF THE DRAWINGS Embodiments of the present invention will now be more particularly described. with reference to the accompanying drawing. in which:

FIG. I shows a sectional view of a revolver. taken in a plane perpendicular to the axis of rotation of the revolver;

FIG. 2 shows a sectional view in plane containing the axis of rotation of the revolver shown in FIG. 1. the part of the revolver mounting the cells and also the arrangement for the control of the reduced pressure supply to the chambers between the internal and external walls of the cells being shown;

FIGS. 3 to 6 show individual control plate members, and the control channels defined thereby. in sectional view in a plane perpendicular to the axis of rotation of the revolver shown in FIGS. I and 2;

FIG. 7 shows a sectional view. in a plane containing the axis of rotation of a second embodiment of the re volver; and

FIG. 8 shows a sectional view in a plane perpendicular to the axis of rotation of the revolver shown in FIG. 7.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS. 1 to 6, the construction of the first embodiment will now be described. FIG. 1 shows four cells 21/22. shown at a. b. c. and def the revolver. each cell being made up of a perforated inner wall 326 (the perforations being shown at 322), an outer wall 327 and a number of intermediate strip members 328 and end closure strip members 329 (FIG. 2 The outer and inner walls of each cell, together with the intermediate and end closure strip member, define a suction chamber 35] associated with the cell. In cell a of the revolver shown in FIG. I there is shown a U-shaped web 330 of packaging material. Each cell is mounted on a holder 24/25, each holder being formed with a cavity therein to reduce the total weight of the revolver. and each holder being rigidly carried by a mounting plate 213, which is also provided with cavities therein to reduce the total weight. Four longitudinal bores 301 a. b. c and d pass through the mounting plate 213 close to the axis of rotation, as shown in FIG. 1, and are connected to the respective cell suction chambers by radial bores 31] and further radial bores 321 in the holders 24/25. Referring to FIG. 2, 55/56 denotes a connecting shaft to be connected to a motor (not shown) to rotate the revolver as desired stepwise, and 308 denotes a shaft coupling connecting the connecting shaft 55/56 to a revolver shaft 55a/S6u. The latter shaft is journalled at ball bearings 305, 305a to be rotatable within and relatively to a support bearing member 58/59 which is stationary at all times during operation of the machine. An end cap 306 is fitted at one end of the support bearing member 58/59, and two members 310 and 206 are fitted at the other end. The parts indicated by numerals 206, 202, 204 and other parts of the revolver arc similar to the correspondingly numbered parts shown in the drawings of co-pending United Kingdom Pat. application No. 53141/72, which discloses in detail a folding arrangements which may be used with the presently described revolver.

The longitudinal bores 301 a, b, c and a extends towards the left (FIG. 2) through the shaft 55u/56a for differing lengths, so that bore 3100 is the longest, bore 301b the second longest, bores 3010 the next longest, and bore 301d the shortest. Numeral 313 denotes a suction chamber within the mounting plate 213. Bolts 215 threaded into the right-hand ends of the bores 301 are effective to seal these ends of the bores. A series of consecutive control plate members, which may be integral with the shaft, defining arcuate peripheral control channels are provided to constitute the portion of the shaft 550/5611 just to the left of the ball bearing 305a. Each of these plate members is sealed against the adjacent one by an O-ring (one of which is shown at 323). The precise configuration of each of the plate members is shown in FIGS. 3 to 6, which show respective ones of the plate members associated with the cells a, b, and d respectively. As shown in FIGS. 3 to 6, each con trol plate member defines a peripheral control channel 302, each of the four control channels 302 subtending the same angle at the axis of rotation of the revolver, and the control plate member in each case having a portion 333 of radius substantially equal to the diameter of the bore passing longitudinally through the sup port bearing member 58/59, and bounding the two ends of the respective control channels 302. The positions of the individual plate members shown at a, b, c and a in FIGS. 3 to 6, along the axis of rotation, are shown in FIG. 2.

Each control plate member is provided with a differ ent number of axial bore portions 301 (FIGS. 3 to 6), the contol plate member a having only one bore portion 301 therethrough adjacent its top region, the plate member b having two bore portions, adjacent its top and left-hand side. the plate member having three bore portions. adjacent its top, left-hand side and bottom, and the plate member d having four symmetrically positioned bore portions therethrough, in a square configurations as shown in FIG. 6. Radial bores 11, b, c and d (FIG. 2) are provided in the support bearing member 58/59. for example in its bottom region as shown in the Figure, the upper ends of the radial bores communicating with the lower portions of the control plate members shown in FIGS. 3 to 6. Pressure equalishing chambers 312 are provided below the radial bores a, b, c and d and communicate at their bottom ends with a connecting chamber 314 which in turn communicates with four individual further bores 315 which open at their lower ends into a vacuum line 332 connected to a vacuum connection nipple 318. Reference numerals 316 and 317 denote a base support member and an adaptor projection respectively.

FIGS. 3 to 6, taken in conjunction with FIG. 2, shown that in the arrangement illustrated the suction chamber of cell a is connected to the connecting nipple 318 by the radial bores 321, the cavity 324/325, the chamber 313, the radial bore 3110, the longitudinally bore 3100 (including the portions thereof extending in a direction parallel to the axis through control plate members a, b, c and d shown in FIGS. 3 to 6), the pressure control channel 302 shown in FIG. 3, the radial bore a through the stationary support bearing member, the left-hand chamber 312, the chamber 314, the left-hand bore 315, and the passage 332. Similarly, the suction chamber of cell b is connected to the connecting nipple 318 by corresponding passages and bores, but in this case the con nection is made through control channel 302b shown in FIG. 4. Similarly, in the case of cell c the connection is through the control channel 302:, but in the case of cell d there is no connection of the corresponding suction chamber of the cell with the connecting nipple 318, since the portion 333 (of full radius) of the control plate member shown in FIG. 6 blocks the corresponding radial bore leading to the corresponding bore through the support bearing member 58/59.

A convenient way of holding together the components of the cells 21/22 is by soldering. By this method, a light, firm cell construction is obtained. The perforated inner wall 326 is preferably provided with perforations all the way round, and may conveniently be made of sheet metal in the manner ofa sieve, as in the case of the outer wall 327 and the strip members 328 and 329. With such a construction, when vacuum is applied to the suction chamber of the cell, the U-shaped web 330 (which may be of viscose or cellulose film, paper, etc.), is held against the inner wall 326 of the cell over the entire surface of that inner wall. The web is thus held to be substantially secure against displacement relative to the wall.

In operation of the embodiment shown in FIGS. 1 to 6, the revolver is rotated stepwise, at a time, so that the various successive operations required to be carried out by the packaging machine may be carried out at successive stations of each cell. Such operations are more fully described in co-pending U.K. Pat. applications Nos. 48I86/72 and 53l4I/72. Vacuum applied at the connecting nipple 318 is effective in the suction chambers of cells a, b and c, as above described, but no vacuum is effective at cell d, to facilitate the expuslion of a cigarette block situated in a cell d by a pusher member acting in a direction parallel to the axis of rotation of the revolver. At all stages in the operation of the machine, it is desired that the cells in the top, left-hand and bottom positions in FIG. 1 should be supplied with vacuum, but that the cell in the right-hand position should not be supplied with vacuum. This is achieved in the condition of the machine shown in the drawings by the particular arrangement of the control plate members and channels 302, which constitute valve means co-rotational with a shaft.

After one 90 step of rotary motion from the position shown in FIG. 1, for example the cell d is in the uppermost position and the cell c in the right-hand position.

In this case, it is the cell c which is to be isolated from the supply of vacuum. In the above mentioned 90 step of rotary motion, each of the control plate members shown in FIGS. 3 to 6 executes a 90 rotation in the anti-clockwise sense, so that the full radius portion 333 of the control plate member of FIG. 5 blocks the downwardly open exit bore shown by the arrow 0 in FIG. 5, thereby blocking the connection between the connecting nipple 318 and the vacuum chamber of the righthand cell in FIG. I in the new position of the revolver. Similarly, the control plate member shown in FIG. 6 has by this time executed a similar 90 anti-clockwise rotation, to bring the full-radius portion 333 of the corresponding plate member out of contact with the upper end of the radial bore through the support bearing member 58/59 which is blocked in the actual position shown in FIG. 6. Clearly, as further 90 steps of rotation take place the successive cells are each isolated from the connecting nipple 318, and thus from the source of reduced pressure, in turn as they occupy the position shown on the right in FIG. l.

In FIGS. 7 and 8, there is shown a second embodiment, in which a vacuum connecting nipple 357 is provided on a boss 351 supported by an arm 355 to be stationary at all times during operation of the machine, the boss 351 containing a segment-shaped chamber 353 with a valve member 354 (FIG. 8). A sealing ring 352 seals the boss 351 against the revolver shaft, shown at 55a/56a. ln FIGS. 7 and 8, the other reference numerals corresponds to those shown in FIGS. 1 to 6, and indicate similar components. The shaft 55a/56a is provided with a cavity 356 for the purpose of the reduction of weight of the assembly to be rotated, and otherwise this second embodiment is of generally similar configuration to that shown in FIGS. 1 to 6. However, it is important to note that in the case of the second embodiment the boss 351 is situated in front of the holders which mount the cells, while in the case of the first embodiment simpler removal, when desired, of the cells and holders is possible, because there is no component corresponding to the boss 351.

With the second embodiment, the bores 301 a, b, c and d are very much shorter, and the segment-shaped chamber 353 with the valve member 354 provides a particularly simple and convenient arrangement for ensuring that the desired one of the four bores 310 a, b, c and d is at each particular step in the rotational motion ofthe revolver shaft isolated from the source of reduced pressure connected at 357.

Some degree of difficulty may in practice be experienced in operation of the second embodiment, particularly with regard to the accurate alignment of the boss 351 by means of the arm 355, which is required to ensure that other devices present in the machine, for example the transverse pushing members, mouthpiece members, lateral sheet guides etc. are not damaged or fouled in operation of the machine. As clearly shown in FIG. 8, as the shaft rotates stepwise 90 at a time anti-clockwise, the bores shown in FIG. 8 at c, b and a successively come against the valve member 354 and thus are sealed from the connecting nipple 357. Thus, the valve member 354 cooperates with the openings defined by the insertion of the longitudinal bores in the shaft with the end surface of the shaft to form valve means co-rotational with the shaft.

The above described embodiments may be employed with the resolvers shown at II and III in the drawings of co-pending U.K. application 48186/72.

It is not essential that the four bores 301a, b, c and d in the first embodiment penetrate into the revolver shaft towards the left in FIG. 2 to different extends, but this arrangement is convenient, as described above.

The above described embodiments may be found to be advantageous relative to an arrangement in which the shortest tranverse dimension of each cell is dis posed in a direction radial of the revolver, since in the latter arrangement cigarettes may be found to fall out rather easily from the revolver cells, which of course is not desired. Furthermore, the presently described arrangements give large space between the successive cells of the revolver, which is desirable to ensure that other parts of the machine, for example the transverse pushing members and ejector members provided for transferring cigarette blocks from one revolver to another and from the final revolver to a storage location have adequate time to withdraw as the revoler executes its stepwise motion.

It is important, to achieve good efficiency of opera tion, that the entire rotary assembly of the revolver by very light in weight. For this reasons, thin sheet metal is an appropriate material from which to construct the parts of the cells, the holders 24/25 being constructed preferably with cavities therein to reduce their weight; similarly the mounting plate 213, and also the shaft 55a/56a. Thus, the weight of the rotatable article receiving means is maintained at an acceptable value. The connecting shaft 55/56 shown at the left in FIG. 2 is preferably tubular, again for the purpose of weight reduction. This shaft may conveniently be made oflight metal.

The first embodiment shows the advantages of easy removal of the cells and holders from the remainder of the rotary assembly of the revolver, and of course good accessibility. This may be of great importance in the case of the revolvers II and III of the arrangement disclosed in co-pending U.K. Pat. application 48186/72.

Where four cells are provided on the revolver, the spacing at the circumference between the successive cells is conveniently about 200 millimetres from the edge of one cell to the adjacent edge of the next cell. The diameter of the revolver is in such a case conveniently 320 millimetres.

In principle, a revolver with six cells is a possible construction, with the same spacing between cells at the circumference of the mounting plate 213, but in this case the diameter would be about 482 millimetres, giving rise to a revolver with a much larger moment of inertial, which may therefore be expected to operate in less efficient manner. Furthermore, with a six-cell revolver, if two mutually opposite cells stand vertically, as shown in FIG. 1 at cells a and c with a four-cell revolver, then no cells stand horizontally as they do with a four-cell revolver. This is generally inconvenient for the feeding-in ofa cigarette block, since the cell receiving the block is obliquely inclined. This difficulty is avoided with an eight-cell revolver, but in this case the outer diameter would be about 640 millimetres, i.e., very much larger than either of the previously described cases, with a correspondingly larger moment of inertia. The acceleration required at the periphery is thus very large, so that the maximum speed of running and efficiency of the machine may well be impaired.

Although adequate space would. of course, be avoidable with an eighbcell revolver for the folding members and other equipment necessary for operation. it may well be found that the most efficient arrangement is a four-cell revolver.

ln previously proposed arrangements, larger revolvers have been employed. and stations have been provided on the revolver in which no operations take place. this representing effectively a waste of space in the revolver. However, with both of the above de scribed embodiments, there is no station at which no operation takes place.

The following advantages may be experienced, with judicious choice of dimensions and operating conditions:

a. smaller lighter revolver construction;

b. only four cells on each revolver to give best efficiency;

c. adequate space between the adjacent cells of each revolver to enable pusher members, effective to transfer the cigarette blocks between the revolvers, to be retracted during the movement of the revolver without great difficulty;

d. use of every cell at each sequential position of the revolver; and

e. the ability to dispose all folding and packageclosing devices to operate at the few cells employed.

Generally speaking. twelve-cell and sixteencell revolvers may be found to be too large and unwieldy for efficient operation using the principle disclosed in the present application.

I claim:

i. A revolver for use as part of a packaging machine for wrapping block-shaped articles in packaging material, the revolver comprising in combination:

a support;

a shaft mounted on said support to be rotatable about the longitudinal axis of said shaft;

article receiving means connected to said shaft to rotate therewith;

cavity defining means provided by wall members of said article receiving means to define a plurality of cavities spaced at angular intervals about said axis and extending in a generally radial direction relative to said axis;

perforate members in each said cavity in spaced relationship with said wall members of the respective said cavity to define cells, each bounded by said perforate members and each adapted to receive one said article, and to define in each said cavity a chamber between said perforate members and said wall members. the dimensions of each said cell being greater in a directional radial of said axis than in a direction tangential-at said cell to a circle passing through all of said cells, said circle having its centre on said axis and being disposed in a plane perpendicular to said axis;

a source of vacuum pressure;

an equal plurality of longitudinally extending passages defined in said shaft, each said longitudinal passage communicating with a respective one of said chambers; and

valve means co-rotational with said shaft, said valve means selectively connecting each said longitudiing:

rial passage to said source on the respective one of said chambers being located within a predetermined range of angular positions relative to said axis.

A revolver as defined in claim 1, further comprisa vacuum chamber defined in said support and communicating with said source;

stationary valve member extending from said support into said vacuum chamber to contact an end surface of said shaft, each of said passages inter secting said end surface of said shaft to define an opening therein. whereby for any given angular position of said shaft. at least one of said openings is closed by said valve member.

A revolver for use as part of a packaging machine for wrapping block-shaped articles in packaging material.

the revolver comprising in combination:

a support;

a shaft mounted on said support to be rotatable about the longitudinal axis of said shaft;

tate therewith;

cavity defining means provided by wall members of said article receiving means to define a plurality of cavities spaced at angular intervals about said axis and extending in a generally radial direction relative to said axis;

perforate members in each said cavity in spaced relationship with said wall members of the respective said cavity to define cells, each bounded by said perforate members and each adapted to receive one said article, and to define in each said cavity a chamber between said perforate members and said wall members, the dimensions of each said cell being greater in a direction radial of said axis than in a direction tangential at said cell to a circle passing through all of said cells. said circle having its centre on said axis and being disposed in a plane perpendicular to said axis;

source of vacuum pressure;

an equal plurality of longitudinally extending first passages defined in said shaft, each said first passage communicating with a respective one of said chambers;

cylinderical surface defined in said support and contacting the peripheral surface of said shaft;

an equal plurality of grooves defined in said shaft in spaced relationship along said axis. each said groove extending around a respective predetermined portion of the periphery thereof and communicating with a respective one of said first passages; and

an equal plurality of second passages defined in said support, each said second passage intersecting said cylindricai surface in a zone thereof encompassing a respective one of said grooves and each communicating with said source, whereby, during rotational motion of said shaft, said source is connected to each said chamber when and only when the respective groove communicating therewith is in communicating relationship with the respective one of said second passages. 

1. A revolver for use as part of a packaging machine for wrapping block-shaped articles in packaging material, the revolver comprising in combination: a support; a shaft mounted on said support to be rotatable about the longitudinal axis of said shaft; article receiving means connected to said shaft to rotate therewith; cavity defining means provided by wall members of said article receiving means to define a plurality of cavities spaced at angular intervals about said axis and extending in a generally radial direction relative to said axis; perforate members in each said cavity in spaced relationship with said wall members of the respective said cavity to define cells, each bounded by said perforate members and each adapted to receive one said article, and to define in each said cavity a chamber between said perforate members and said wall members, the dimensions of each said cell being greater in a directional radial of said axis than in a direction tangential-at said cell - to a circle passing through all of said cells, said circle having its centre on said axis and being disposed in a plane perpendicular to said axis; a source of vacuum pressure; an equal plurality of longitudinally extending passages defined in said shaft, each said longitudinal passage communicating with a respective one of said chambers; and valve means co-rotational with said shaft, said valve means selectively connecting each said longitudinal passage to said source on the respective one of said chambers being located within a predetermined range of angular positions relative to said axis.
 2. A revolver as defined in claim 1, further comprising: a vacuum chamber defined in said support and communicating with said source; a stationary valve member extending from said support into said vacuum chamber to contact an end surface of said shaft, each of said passages intersecting said end surface of said shaft to define an opening therein, whereby for any given angular position of said shaft, at least one of said openings is closed by said valve member.
 3. A revolver for use as part of a packaging machine for wrapping block-shaped articles in packaging material, the revolver comprising in combination: a support; a shaft mounted on said support to be rotatable about the longitudinal axis of said shaft; article receiving means connected to said shaft to rotate therewith; cavity defining means provided by wall members of said article receiving means to define a plurality of cavities spaced at angular intervals about said axis and extending in a generally radial direction relative to said axis; perforate members in each said cavity in spaced relationship with said wall members of the respective said cavity to define cells, each bounded by said perforate members and each adapted to receive one said article, and to define in each said cavity a chamber between said perforate members and said wall members, the dimensions of each said cell being greater in a direction radial of said axis than in a direction tangential - at said cell - to a circle passing through all of said cells, said circle having its centre on said axis and being disposed in a plane perpendicular to said axis; a source of Vacuum pressure; an equal plurality of longitudinally extending first passages defined in said shaft, each said first passage communicating with a respective one of said chambers; a cylinderical surface defined in said support and contacting the peripheral surface of said shaft; an equal plurality of grooves defined in said shaft in spaced relationship along said axis, each said groove extending around a respective predetermined portion of the periphery thereof and communicating with a respective one of said first passages; and an equal plurality of second passages defined in said support, each said second passage intersecting said cylindrical surface in a zone thereof encompassing a respective one of said grooves and each communicating with said source; whereby, during rotational motion of said shaft, said source is connected to each said chamber when and only when the respective groove communicating therewith is in communicating relationship with the respective one of said second passages. 